Computer displays with aspect ratios wider than 4:3 are also called widescreen. Widescreen computer displays are typically of the 16:9 or 16:10 aspect ratio. In 2008, the computer industry started to move over from 4:3 and 16:10 to 16:9. Many 16:9 computer displays can be found in resolutions of 1024×576, 1152×648, 1280×720, 1600×900, 1920×1080, 2560×1440 and 3840×2160, while 1366×768 is an approximate ratio to 16:9 with its true ratio of 683:384.

Until about 2003, most computer monitors had a 4:3 aspect ratio and some had 5:4. Between 2003 and 2006, monitors with 16:10 aspect ratio became commonly available, first in laptops and later also in standalone computer monitors. Reasons for this transition was productive uses for such monitors, i.e. besides widescreen movie viewing and computer game play, are the word processor display of two standard letter pages side by side, as well as CAD displays of large-size drawings and CAD application menus at the same time.[2][3] 16:10 became the most common sold aspect ratio for widescreen computer monitors until 2008.

In 2008, the computer industry started to move from 4:3 and 16:10 to 16:9 as the standard aspect ratio for monitors and laptops. A 2008 report by DisplaySearch cited a number of reasons for this shift, including the ability for PC and monitor manufacturers to expand their product ranges by offering products with wider screens and higher resolutions, helping consumers to more easily adopt such products and "stimulating the growth of the notebook PC and LCD monitor market".[4]

By 2010, virtually all computer monitor and laptop manufacturers had also moved to the 16:9 aspect ratio, and the availability of 16:10 aspect ratio in mass market had become very limited. In 2011, non-widescreen displays with 4:3 aspect ratios still were being manufactured, but in small quantities. The reasons for this according to Bennie Budler, product manager of IT products at Samsung South Africa was that the "demand for the old 'Square monitors' has decreased rapidly over the last couple of years". He also predicted that "by the end of 2011, production on all 4:3 or similar panels will be halted due to a lack of demand."[5]

In March 2011, the 16:9 resolution of 1920×1080 became the most commonly used resolution among Steam users; the previous most common resolution was 1680×1050 (16:10).[6] In April 2012, the 16:9 resolution of 1366×768 became the most commonly used resolution worldwide; the previous most common resolution was 1024×768 (4:3). The third most common resolution at the time was 1280×800 (16:10).[7]

Since 2005 most video games are mainly made for the 16:9 aspect ratio and 16:9 computer displays therefore offer the best compatibility.[8] 16:9 video games are letterboxed on a 16:10 or 4:3 display or have reduced field of view.[9] 4:3 monitors have the best compatibility with older games released prior to 2005 when that aspect ratio was the mainstream standard for computer displays.[9]

Around 2000 the DVDs and TV broadcasts shifted from 4:3 to 16:9. Today the TV and DVDs are in 16:9 (1.77:1) or 1.85:1 format; 16:9 displays are optimal for their playback on a computer. 16:9 material on a 16:10 or 4:3 display will be letterboxed. In data processing or viewing 4:3 material such as older films, older TV broadcasts or older digital photographs, the widescreen (16:9, 16:10) will be letterboxed.[10]

When displays are marketed the quoted size usually is the diagonal measurement of the display area. Because of the different ratio, a 16:9 computer monitor will have a smaller area than a 4:3 computer monitor of the same advertised size.

The table below is a comparison between monitors with a diagonal of 23 inches (58 cm).[13]